Claude Code Ultimate Guide

Claude Code Ultimate Guide

Florian BRUNIAUX · Fractional Chief AI Officer

13 years from developer to CTO / VP Eng · Blog ↗ · Projects ↗

Learn Claude Code, build reliable agents, and scale their use safely. The website is the primary reading and discovery interface. This repository contains the canonical Markdown sources, reusable files, machine-readable indexes, and contribution history.

Start here: complete a first task online · browse the guide portal · open the complete sitemap · read the Markdown source

Choose your next step

The table below is generated from machine-readable/navigation.json. The same contract feeds the public sitemap, so the repository and website expose the same intent model.

Why this guide exists

Claude Code documentation explains the product. This guide connects product behavior to engineering decisions: what belongs in context, when to use an agent instead of a skill, how to verify generated work, and which controls matter when usage moves beyond one developer.

The guide favors explicit trade-offs and verifiable procedures. Where evidence is incomplete, the relevant page should preserve that limit instead of presenting one workflow as universal.

Start

Install Claude Code

Anthropic recommends the native installer, which updates itself:

# macOS, Linux, WSL

curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell

irm https://claude.ai/install.ps1 | iex

Alternatives that do not auto-update: brew install --cask claude-code, winget install Anthropic.ClaudeCode, or npm install -g @anthropic-ai/claude-code (Node.js 22+). See the official setup page.

Verify the installation and authenticate:

claude --version

claude doctor claude auth login

The Quick Start chapter documents installation alternatives, authentication, updates, permission modes, and common first-day failures.

Complete a first task

Open a small repository with a clean or understood Git state, then start Claude Code:

cd your-project

claude

Give Claude a bounded request that includes the expected result and verification:

Explain how this project runs its tests. Do not modify files.

Name the relevant commands and cite the files that define them.

Before asking Claude to edit code, add a project-level CLAUDE.md that records the commands and constraints Claude must follow:

# Project instructions

Commands

• Test: npm test
• Lint: npm run lint

Boundaries

• Do not edit generated files.
• Do not change dependencies without approval.
• Run the relevant tests before claiming completion.

Continue with the first workflow or use the starter CLAUDE.md templates.

Choose a learning path

For a personalized route, use the repository onboarding prompt:

claude "Fetch and follow the onboarding instructions from: https://raw.githubusercontent.com/FlorianBruniaux/claude-code-ultimate-guide/main/tools/onboarding-prompt.md"

Build

Agent engineering

An agent is one component of a larger system. The surrounding harness controls context, tools, permissions, state, stopping conditions, recovery, and evaluation.

Context and memory

Context quality affects every tool call and decision. Start with project instructions, add specialized context only when a recurring task needs it, and test whether the extra material changes behavior.

Workflows

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